Seems to me that the only way they are getting Trump off that stage is on his own two feet. He's a big, fat load. So they aren't carrying him, and dragging him probably is slow, awkward, and leaves him exposed. The car was waiting close by, so they get him up with the intentions of shielding him and moving him to the vehicle. The problem with this is that he's an uncooperative fuck, who thinks he's invincible. And he's old. So he doesn't bend down to let himself be shielded, move quickly, or do anything but feed on whatever adrenaline might help to expedite his egress to, instead, demand someone retrieve his shoes and play it up to the crowd. Plus, there's a ramp, and we know he's not moving quickly down that seemingly-insurmountable obstacle.
It's pretty widely reported that he had the B-team, which was spread thin due to budget and location. The whole thing was a clusterfuck, but Trump being Trump doesn't make it easy when shit goes south.